Lecture 3 Flashcards
What seperates the two vertebral bodies?
Intervertebral disc (IVD) joints
How much of the length of the vertebral coulumn does teh IVDS make up?
20-33 %
What is the function of the IVD?
The discs transmit load from one vertebral body to the next.
IVDS decrease in size from the cervical to lumbar as the vertebral body decreses in size
FALSE
IVDS INCREASE in size from the cervical to lumbar as the vertebral body INCREASE in size
What joints are IVDS?
Cartilaginous joints of the symphysis type
What does the ratio between disc thickness and vertebral body height determine?
The available motion
ie. great ration =great mobility
Which region is the ratio the greatest
Cervical region
How many Intervertebral discs do we have?
23
Describe the IVDS shape
Discs are wedged shaped, contriubte to the curves of the spine
What is the shape of the cervical IVD
kidney
Do the cervical IVDS extend to the edge of teh vertebral body
No, the cervical IVDS do not extend to the edge of teh vertebral body due to the uncinate processes
What are the parts of the Intervertebral Discs?
Nucleus Pulpous
Annulus Fibrosus
Vertebral endplate
Describe the Nucleus pulposus
Central gelatinous mass
Soft, highly hydrophilic(water-loving), contains glycosaminoglycans (GAG)
No clear boundary between nuclear and outer fibres
Describe the Annulus fibrous ring
Surrounding fibrous ring
Series of angular bonds
Aprox 20 bands per lamina direction of bands alternates
How many bands per lamina - Anulus fibrosus?
aprox 20 bands, direction of bands alternates
Describe the vertebral endplate
Hyaline cartilage layers on superior and inferior surfaces.
3 major Functions of vertebral endplate
1.Protects from pressure and atrophy
2.Confine nucleus pulposus and annulus fibrosus
- Semi permeable membrane
What anchors the IVD to the vertebral body.
The IVD is anchored by Annulus fibrosus and cartilaginous endplate to the vertebral body by sharpeys fibres
What are sharpeys fibres
strong collagenous fibres, connection periosteum to bone
What are the 3 parts of IVD composed of?
Water
Collagen
1. Type I annulus fibrosus, gives tensile strength
2. Type II nucleus pulposus, give compressive strength
Proteoglycans
Elastin - gives flexibility
What types of collagen are there
Type I and Type II
Where is Type I collagen found in the IVDs?
Annulus fibrosus
Where is Type II collagen found in the IVDS?
Nucleus pulposus
What does Type I collagen do?
Gives tensile strength
What does Type II collagen do?
Give compressive strength
What are 3 stages are there of herniated discs?
PROTUSION
deformation of annulus fibrosus only
EXTRUSION
nucleus pulposus becomes extruded - remains within the disc
SEQUESTRATION
nucleus pulposus breaks through annulus fibrosus lies outside disc in neural canal
Protusion of Herniated disc
deformation of annulus fibrosus only
Extrusion of Herniated disc
nucleus pulposus becomes extruded - remains within the disc
Sequestration of herniated discs
nucleus pulposus breaks through annulus fibrosus lies outside disc in neural canal - will put pressure on the spinal nerves
What ligaments support the IVD
- ANTERIOR LONGITUDINAL LIGAMENT (ALL)
- POSTERIOR LONGITUDINAL LIGAMENT (PLL)
ALL
Anterior Longitudinal Ligament
Describe The ALL
Runs along the anterior surfaces of the vertebral bodies
Where does the ALL extend from
Axis C2 to the Sacrum S5
Where is the ALL thicker
in thoracic region
Above the axis what is it cntinious with ?
The Anterior atlantoaxial and anterior atlantooccipital ligs
What does the fibres ALL adhere to ?
To the margin of the Vertebral body and Intervertebral discs thicker opposite the bodies than the IVDS
What is the ALL continous with above C2?
anterior atlanto-occipital membrane above C2.
What is the ALL made up of?
Three layers of thick bundles of collagen
Describe the layers
- Superficial Layer
- longest extends between 4-5 vertebrae - Middle
- extends between 2-3 vertebrae - Deep layer
-extends between adjacent vertebrae
Describe the Middle Layer
- extends between 2-3 vertebrae
Describe the Superficial Layer
longest
extends between 4-5 vertebrae
Describe the deep layer
-extends between adjacent vertebrae
what happends to the ALL in flexion
It is compressed in Flexion
What happends to the ALL in extension?
It is stretched in extension
How long is the ALL in relation to the PLL
2x as long as the PLL
PLL
Posterior Longitudinal Ligament
Where is the PLL situated?
Within the vertebral canal
Where does the PPL extend?
from the Axis to the Sacrum S5
Where is the PLL thicker?
Thoracic region
What happens to the PLL at the axis?
It is continous with tectorial (broader) membrane
Where do the PLL fibres adhere to at the vertebrae?
- intervertebral discs
adjacent margins of the vertebrae
How many layers does the PLL have?
Two layers
Name the PLL layers
Superfical and deep
What happens to the PLL in Flexion
Stretched
What is teh PLL continious with above C2.
Tectorial membrane
What happens to the PLL in extension
Slack
What 4 features does a typical synocial joint have?
1.Hyaline Cartilage
- Joint Capsule
2Inner synocial membrane
3 Outer Fibrous capsule
4 Synovial Fluid
In synovial joint what is hyaline cartilage function?
Covers ends of the two bones
- reduces friction and absorbs shock
What is the function of the inner synovial membrane?
prodcuces synovial fluid
What is the function of the outer fibrous capsule?
stability
What is the function of the synovial fluid?
Nourishes cartilage
Lubricates joint
Reduces Friction
Contains Hyaluronate
Glycoproteins
What are the accessory structures of a typical synovial joint and what are their functions?
Ligaments - stability
Tendons -stabilise and move
Menisci- congruency
Disc
Bursae
Fat pads
What is the bursae
a sac of synovial fluid underneath the tendon between bone and tendon
reduces friction
to prevent bursitis
Function of Fat pad
shock absorbers
Function of the menisci
congruency
Uncovertebral joint
Uncinate process - inferior vertebrae
Bevelled surface - superior vertebrae
What are uncovertebral joints, and where are they located?
Uncovertebral joints are small synovial joints located between the uncinate processes of the inferior vertebrae and the beveled surfaces of the superior vertebrae in the cervical spine.
What is the function of uncovertebral joints?
Uncovertebral joints stabilize the neck by providing additional support and limiting excessive movement between the lateral parts of adjacent vertebrae.
Describe the structure of the uncinate processes.
The uncinate processes project superiorly from the superior surface of the vertebral body in the cervical spine.
How do the beveled surfaces of the superior vertebrae contribute to the formation of uncovertebral joints?
The edges of the inferior surface of the vertebral body in the superior vertebrae are concave, forming beveled surfaces that articulate with the uncinate processes of the inferior vertebrae.
What are the uncinated process
Project superiorly from the superior surface of the vertebral body
What is the bevelled surface
Edges of inferior surface of vertebrae body are concave
What is osseous proliferation, and where is it commonly observed?
Osseous proliferation refers to the formation of bony outgrowths and is commonly observed in uncovertebral joints.
Where are uncovertebral joints located in relation to the intervertebral foramen?
Uncovertebral joints are located anterior to the intervertebral foramen.
What are the potential consequences of arthritic changes in uncovertebral joints?
Arthritic changes in uncovertebral joints can potentially lead to compression of spinal nerves and restricted movement.
How can osseous proliferation in the uncovertebral joints affect spinal nerves?
Osseous proliferation in the uncovertebral joints can compress or impinge upon spinal nerves, leading to symptoms such as pain, numbness, or weakness.
What role do uncovertebral joints play in restricting movement when affected by arthritic changes?
Arthritic changes in uncovertebral joints can cause stiffness and reduced flexibility in the neck region, limiting the range of motion.
Question: What is the orientation of the cervical region of the spine?
The cervical region has an oblique orientation.
Which movements are possible in the cervical spine?
Flexion, extension, lateral flexion, and rotation are possible in the cervical spine.
Where is the most rotation observed in the cervical spine?
The upper cervical spine exhibits the most rotation.
What limits rotation in the cervical spine?
Lower cervical spine limits rotation but allows for more lateral flexion.
Where is a facet joint found
Found between the SAP / IAP
WHat joint is a facet joint
Synovial joint
What is the function of the uncovertebral joints
Stabilize the neck
Meniscoids
Fibro-adipose structure in the thoracic and lumbar facet joints
What is the function the Mensicoids do?
Improves congruency and thus stability
Highly vascularised and innervated with nociceptors
What ligaments suport the facet joints
Ligamentum Flavum
Supraspinous ligament
Ligamentum Nuchae
Interspinous ligament
Intertransverse ligament
Why is the ligamentum flavum known as the yellow ligament
Has thick elastic ligament - yellow colour
What does the Ligamentum flavum connect?
Lamina to lamina- runs inside the vertebral foramen
How many parts does each ligament consist of ?
Two lateral parts
Where does the Ligamentum flavum run from?
C2 to sacrum
Where is the Ligamentum flavum found?
Above the axis it is continous with the posteior atlantoaxial and posterior atlantoocciptal ligs
What ligaments are continuous with the ligament above the axis vertebra
The Ligamentum Flavum above the axis vertebra is continuous with the posterior atlantoaxial ligament and posterior atlantooccipital ligament.
Where is the Ligamentum flavum the strongest?
Lower Thoracic region
what does the Supraspinous ligament connect?
Connects the SP of adjacent vertebrae
Where does Supraspinous ligament extend?
C7 to the Sacrum S4
Why doesnt the Supraspinous ligament run to the S5?
S5 has no spinous process, sacral hiatus
Describe the Supraspinous ligament.
Thicker and broader in the lumbar than in the thoracic
Where is the Supraspinous ligament continous with the Ligamentum nuchae?
Above c7
What happens above C7 with regards to the Suprasspinous ligament?
Above C7 it is continuous with Ligamentum nuchae
Where is the the Suprasspinous ligament is continuous with Interspinous ligament?
Between the spinal process
What is the Ligamentum nuchae a continuation of?
supraspinous ligament
Where does the Ligamentum nuchae extend from ?
from EOP and medial nuchal line to SP of C7
Where does the Ligamentum nuchae attched to?
It is attached to the posterior tubercle of the atlas and SP of cervical vertebrae
What is the function of the Ligamentum Nuchae
Acts to resist flexion of the neck
What orientation characterizes the thoracic region of the spine?
The thoracic region has a coronal orientation.
Which movements are possible in the thoracic spine?
Flexion, extension, lateral flexion, and rotation are possible in the thoracic spine.
Why is movement during flexion and extension limited in the thoracic spine?
Movement during flexion and extension is limited in the thoracic spine due to the presence of the rib cage and facet orientation.
At which vertebral levels is the least movement observed in the thoracic spine?
The least movement in the thoracic spine is observed around T5 or T6/7 levels.
What is the orientation of the lumbar region of the spine?
The lumbar region has a sagittal orientation characterized by “J hooks.”
Which movements are limited in the lumbar spine?
Rotation is limited in the lumbar spine, while flexion and extension are predominant movements.
What structures do the interspinous ligaments connect?
Interspinous ligaments connect adjoining spinous processes.
How does the interspinous ligament vary in thickness and development across different regions of the spine?
The interspinous ligament is narrow and elongated in the thoracic region, thicker in the lumbar region, and only slightly developed in the cervical region.
What is the anatomical extent of the interspinous ligament?
The interspinous ligament extends from the root to the apex of adjacent spinous processes
What ligaments does the interspinous ligament meet anteriorly and posteriorly?
The interspinous ligament meets the ligamentum flavum anteriorly and the supraspinous ligament posteriorly.
Where do intertransverse ligaments pass between?
Intertransverse ligaments pass between the transverse processes of adjacent vertebrae.
To what structures are intertransverse ligaments attached?
deep muscles of the back.
How do intertransverse ligaments differ across different regions of the spine in terms of their appearance and thickness?
Intertransverse ligaments are only present as a few fibers in the cervical region, barely discernible from adjacent muscles in the thoracic region, and thin and membranous in the lumbar region.
What structures do the ligamentum flavum continue as from the axis to the occiput?
From the axis to the occiput, the ligamentum flavum continues as the posterior atlantoaxial ligament and the posterior atlantooccipital ligament.
